Bobbins for sewing machines



March 16, 1965 F. G. CRI-:TER E'rAl.

BoBBINs FOR SEWING MACHINES Filed Jan. 7, 1963 Frederick G Crerer Sian/ey J. Keherer Y ATTORNEY United States Patent O 3,173,625 BOBBINS FOR SEWING MACHINES Frederick G. Creter, Brcktown, and Stanley J. Ketterer, Morris Plains, NJ., assignors to The Singer Company, a corporation of New Jersey Filed Jan. 7, 1963, Ser. No. 249,629 Claims. (Cl. 242-11S.62)

This invention relates to sewing machines and more particularly to bobbins especially adapted, though not necessarily restricted, for use with the loop takers of sewing machines of the class wherein the bobbin of the sewing machine can be wound without removing it from the loop taker. One form of this class of sewing machine is shown and described in United States patent application Serial No. 133,896, filed August 25, 1961, in the name of Stanley J. Ketterer, now Patent No. 3,115,- 855.

One of the primary objects of the present invention is to provide an improved bobbin suitable for use as part of the loop taker of sewing machines.

Another object of the invention is to provide inexpensive plastic bobbins of an improved design.

A further object of the invention is to provide a multipart plastic bobbin which is strong and durable and which can be easily manufactured, assembled, disassembled and reassembled.

A still further object of the invention is to provide a two-part plastic bobbin having a body portion and flange portion which can easily be connected to one another.

A further object of the invention yis to provide a twopart plastic bobbin having cylindrical aligning surfaces which assure that the two parts will always be assembled concentrically.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, cornbinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings:

FIG. 1 is a top plan view of a portion of a sewing machine showing a loop taker equipped with a multipart plastic bobbin embodying the present invention,

FIG. 2 is a vertical sectional view taken substantially on the line 2-2 of FlG. 1,

FG. 3 is an enlarged cross sectional View showing the body and flange portions of the multi-part assembled bobbin,

FIG. 4 is a reduced scale exploded perspective view of the bobbin showing, among other things, the inside surfaces of the body and flange portions thereof,

FIG. 5 is a reduced scale perspective view showing, among other things, the outer surface of the body portion of the bobbin, and

FlG. 6 is a reduced scale perspective view showing the outside surface of the flange portion of the bobbin.

A sewing machine 16, portions of which are illustrated in FlGS. l and 2, comprises, in part a frame including a bed 17, a throat plate 18 having a feed dog slot 19 and a needle hole 21 designed respectively to accommodate a feed dog 22 and a needle 23. The sewing machine 16 also has a vertical axis rotary hook type loop taker, indicated generally by the numeral 24. The loop taker 24 has a beak 25 formed on an upwardly open cupshaped member 26 mounted on the upper end of a vertical hollow shaft 27. The cup-shaped member 26 and the shaft 27 preferably rotate at a speed of two revolutions for each reciprocation of the needle 23. The up- "ice per end of the cup-shaped member 26 extends inwardly as at 28 and has formed on its inner circumference an infacing raceway 29. An annular bobbin case 32 is partly housed Within the cup-shaped member 26 and the bobbin case 32 has an outfacing external semicircular raceway 33 which is complemental to the raceway 29. The bobbin case 32 is restrained from rotary movement by a means presently to be described and the cup-shaped member 26 rotates about the non rotating bobbin case 32. To complete the circular form of the bobbin case 32 the ends of the bobbin case raceway 33 are joined by a substantially semicircular arm 34. The bobbin case 32 is formed with oppositely-faced, spaced abutments 36 and 37 which are engaged by the ends of spaced fingers 41 and 42 formed as part of a bracket 43 slidably secured to the bed 17 by two screws 44. A leaf spring 46 carried on the bracket 43 and extending between the linger 42 and the abutment 37 serves to cushion any vibrations of the bobbin case 32.

Disposed Within the cup-shaped member 26 is a flat annular disc 47 having formed on its upper side an upstanding annular rib 48 and a driving pin 49. The lower side of the disc 47 carries a hub 5) Which secures the disc 47 to the upper end of a rod S1 located inside the hollow shaft 27.

The function of the disc 47, the rib 48, the pin 49 and the rod 51 are fully set forth in United States Patent No. 3,115,855, supra, therefore, suflice it to say that the rod 5l and the disc 47 may be raised to cause the pin 49 to drive a bobbin hereinafter described.

A bobbin hold-down arm 52 is pivoted on a pin 53 carried by the bobbin case 32. The end of the arm 52 carried on the pin 53 is enlarged, as at 54, and the er1- largement is engaged by one end of a leaf spring 56 carried beneath the bobbin case 32 and the tension of the spring 56 may be adjusted by turning a screw 57. The free or distal end 53 of the arm 52 has a laterally extending handle 59 designed to facilitate turning the arm 52 on the pin 53. The end 58 of the arm has on its lower surface (FIG. 2) a downwardly protruding semispherical bearing 61 the function of which will presently be described.

The bobbin case 32 and the cup-shaped member 26 house a multi-part plastic bobbin, indicated generally by the numeral 64, and the complete bobbin 64 is formed by two separable parts, namely a body part 67 and a flange part 68. The body part 67, which is preferably made of clear plastic, is circular in form and has a concentrically located cylindrical hub 70. The hub 70 extends axially inwardly from a fiat circular plate 71 having an inside surface 72 and an outside surface 73. The hub 70 is formed with a concentrically located internal threaded hole or connecting member 74. The innermost p0rtion of the hub 70 takes the form of a reduced diameter end 75 having an accurately formed external cylindrical surface 75' (FIG. 4). A plane mating surface 76, perpendicular to the axis of the body part 67, is formed on the hub 70 and extends radially from the base of the end 75, and the outer edge of the plane surface 76 is beveled as at 77. The outer side 73 of the body part 67 is formed with a recessed circular groove '78 and approximately 45 of the circumference of this groove is partly lled with a face-earn having an axially extending abutment 79 which may be engaged by the driving pin 49, previously described. The flange part 68, which is preferably made of clear plastic, is also circular but of a larger outside diameter than the body part 67. The flange part 68 is formed with a concentrically located externally threaded stud or connecting member 80, and the stud 80 extends axially inwardly from a substantially flat circular plate 81 having an inside surface 82 and an outside surface 83. The base of the stud 80 is surrounded by an accurately outside diameter of thel previously mentioned cylindrical surface 75. Because of this, thetwo surfaces 75 and 85' engage one another in such a manner as to guarantee that the body part 67 will be concentric withV the flange part 68. The outer edge of the groove'85l defines the inner circumference offa. plane mating 'surface 86 (FIG. 4) which is perpendicular to thev axis of the flange part 68. Thev plate 81 and the Ystud 80 are not completely apertured and thus the flange part 68 does not have a hole passing all the way therethrough. However, the outside surface 83 of the plate 81 isformed with a concentrically located, sernispherical bearing depression 88 which 'is of such size and lshape as to receive the previously mentioned 'semispherical bearing 61. The stud 80, while not having an aperture extending allvthe way therethrough, is hollow andunthreaded adjacent to its free or distal end 89. The ange part 68, in addition to having the plate 81, is formed with a hub 90 which extends away portion of the bobbin 64 on which thread may be wound.

Preferably, the threaded hole 74 andthe threaded stud 80 will engage-one -another with what is knownV as a class two tit. In other words the tit of the threads is relatively loose and the stud 80 can easily be threaded intoy the hole 74. Thus the concentricity of the part 67 andY the part 68 depends on the two accurate surfaces 75-and 85.y and not on the threads 74 and 80.`

'The parts 67 and 68 are assembledin the following manner. The body part 67 is placed adjacent to the body part 68r yso that the inside surfaceV 72 of the part 67 faces the inside surface 82 of the part 78. Then the Unthreaded free end 89 of the stud 80 is entered into the threaded hole 74 until ythe threaded portion of the stud 80 engages the threads of the hole 74.. Then the two parts are relatively rotated until plane surfaces 76 andA 86 abut. When'the surfaces 76 and 86 abut, the bevel 77 and a portion of the surface 86 form an annular thread gripping notch 91. The 'assembled bobbin 64 may then be placed into the loop taker 24 by rst grasping thev handle 59 and turning the arm 52 upwardly against the action of the spring 56. When the arm 52 is raised (dash-dash position FIG. 2), the assembled bobbin 64,.

with'the `body 67 lowermost, is dropped into the .bobbin machinefunctionsY that is the.4 bobbin passes through a thread loop cast otl by the needle. When the disc 47 andgthe rod 51 are in their raised position (as shown by solid lines in fFIG. 2) the pin 49 enters the groove 78 and engages the abutment 79 and links the bobbin to the cup-shaped member 26. land, rotation ofy the vcup-shaped member 26y causes the beak 25 kto engage andwrapthread 'e around the bobbin 64 in such a way that the lirst turn of thread is wedged into thenotch 91 thereby securing V,can be accurately and inexpensively manufactured-.

(b.) The circular groove `78 and the abutment 79 and its cam face permit placingthebobbin 64 on the annular disc 47 without regard to registration of the pin 49 with the abutment 79. .Y Y y. f (c) The semisphericaldepression 88fassures that the Vbobbin 64 will be properly centered whenever the bearing.61 ofthe arm 52 is lowered int'o the depression 88. As previously stated, the bobbin 64 will'always be properlyv centered .even though it may-have been placed olf center in the bobbin Vcase 32 before the arm 52 is lowered.

on the bobbin.

sewing machie'y operator to determine approximately how case 32 untilV the outer circumferential edge ofthe inside i surface 82 of the plate 81 rests on an annular ledge 92- (FIG. 2) formed on the bobbin case 32, it being noted that the inner diameter of the ledge 92 is smaller than f the diameter of the plate 81. Then the arm 52 is lowered to the solid line position shown in FIG. 2. Even though The. groove 85,7formedin Vthe flange part 68," receives the end 75 ofthe hub 70 thereby permitting both the threads of the stud 80 andthe threads of the vhole 74 to be long. enough to provide a strong yand durable connection between the two parts 67 and 68.y

(g)V The indicia 96, 97 and 98,` which is formed on theclear plastic liange part 68, makes it possible Vfor a much thread is wound on the bobbin. v

' (h) The cylindricalaligning surfaces 75 and 85, assure concentricityof the v`parts 67 and 68. v

Havingthus set forththe nature of this invention, what is claimed'herein is Y Y v l. Aiwa-part* bobbin adapted'foruse Awith a sewing machine having a loop taker, said sewing machine ,being ofthe class wherein the bobbin can be wound without form of three concentric` rings 9.6, 97 'and 98, which may Y invention, function inageneral .manner similar'to the functioningrof the loop taker and bobbin. shown and described in the United States Patent No. 3,115,855,supra,

thereforerit will be suicient testate. that, when the disc"y 47 and the rod-51 are in their lowered position (as shown in dash-dash lines in FIG. 2), the bobbin 64 functions in muchrthelsame manneras thebobbin of `any-lockzstitch `removing it from the loop taker, said bobbin comprising a'body part having a lirst annular hub portion provided withaV concentrically locatedfthreaded hole, a reduced diameter end formed on said hub portion, a'flange part,

Va threaded stud formed on said flange'part and being of 'end Vof the 'lrstr hubportionon saidl body part, said hub portions being Vof Substantially equal outer diameters andv providing a winding surface forV fwinding thread thereon. Y2. A` two-part bobbin adaptedfor use Awith a sewing machine having a loop taker, `said sewing machine kbeing Vof the class wherein thebobbincan be wound without removing it from the loop taker, said bobbinrcomprising a flange part, and a body part, one of said parts having a first annular hub portionprovided with a concentrically located threaded hole, a reduced diameter end formed on said hub portion, the other vof, saidparts having a threaded a "FAIM a stud of such size and shape as to engage said threaded hole, the base of said threaded stud being surrounded by a second annular hub portion integral with said stud and defining a cylindrical groove surrounding said stud and said grove being of such size as to receive the said reduced diameter end on said iirst hub portion, said hub portions being of substantially equal outer diameters and providing a Winding surface for Winding thread thereon.

3. A bobbin especially adapted for use with a sewing machine having a loop taker, said sewing machine being of the class wherein the bobbin can be Wound Without removing it from the loop taker, said bobbin comprising a first part having a circular plate and a plane surface extending perpendicularly to the axis of said bobbin, a second part having a circular plate and a plane surface extending perpendicularly to the axis of said bobbin, a bevel formed on one of said plane surfaces, an externally threaded member carried on one of said parts, and an internally threaded member carried on the other or" said parts, the said two threaded members ioining to bring said two plane surfaces and said bevel adjacent to one another to forni an annular thread gripping groove such that' the innermost annular portion of the bevel on the one part joins the plane surface on the other part to grip the thread.

4. A two-part bobbin cornprisiruT a body part having a first annular hub portion provided with a concentrically located threaded hole, a reduced diameter end formed on said hub portion and having an accurately formed external cylindrical surface, a flange part, a threaded stud formed on said flange part and being of such size and shape as to loosely engage said threaded hole, the base of said threaded stud being surrounded by a second annular hub portion integral with said stud and defining a cylindrical groove surrounding said stud and said groove having an accurately formed internal surface of such size as to accurately receive the said external surface of said reduced diameter end of the first hub portion on said body part, said hub portions being of substantially equal outer diameters and providing a Winding surface for winding thread thereon.

5. A two-part bobbin comprising a transparent plastic body part having a circular plate and said circular plate having on one side thereof a cylindrical hub provided with a mating surface and a concentrically located threaded hole, a reduced diameter end formed on said cylindrical hub and having an accurately formed external cylindrical surface, the other side of said body part having a circular groove a portion of the circumference of which is partly filled with a face cam having an axially extending abutment, a transparent plastic ilange part having a circular plate which is larger in diameter than the circular plate of the said body part', a threaded stud formed on one side of said iiange part and being of such size and shape as to loosely engage said threaded hole on said body part, the base of said threaded stud being surrounded by an annular hub having a mating surface and said annular hub being formed integral with said stud and defining a cylindrical groove surrounding said stud and said annular hub having an accurately formed internal surface of such size as to accurately engage the external surface of said reduced diameter end of the hub on said body part, the other side of said flange part being formed with a semi- Spherical bearing depression.

References Cited in the tile of this patent UNITED STATES PATENTS 487,704 Back Dec. 13, 1892 507,124 Haynes et al. Oct. 24, 1893 1,324,171 Propst Dec. 9, 1919 1,560,120 Teed Nov. 3, 1925 1,593,012 Bryant July 20, 1926 1,611,472 Marshall Dec. 21, 1926 1,924,745 Mossberg Aug. 29, 1933 2,340,574 Ashworth Feb. 1, 1944 2,475,399 Nelson luly 5, 1949 2,573,598 Perry et al Oct. 30, 1951 2,643,828 Vincent Iune 30, 1953 3,041,005 Wallace June 26, 1962 3,106,176 Doerner Oct. 8, 19'63 FOREIGN PATENTS 123,963 Great Britain Mar. 13, 1919 765,748 France Mar. 31, 1934 

1. A TWO-PART BOBBIN ADAPTED FOR USE WITH A SEWING MACHINE HAVING A LOOP TAKER, SAID SEWING MACHINE BEING OF THE CLASS WHEREIN THE BOBBIN CAN BE WOUND WITHOUT REMOVING IT FROM THE LOOP TAKER, SAID BOBBIN COMPRISING A BODY PART HAVING A FIRST ANNULAR HUB PORTION PROVIDED WITH A CONCENTRICALLY LOCATED THREADED HOLE, A REDUCED DIAMETER END FORMED ON SAID HUB PORTION, A FLANGE PART, A THREADED STUD FORMED ON SAID FLANGE PART AND BEING OF SUCH SIZE AND SHAPE AS TO ENGAGE SAID THREADED HOLE, THE BASE OF SAID THREADED STUD BEING SURROUNDED BY A SECOND ANNULAR HUB PORTION INTEGRAL WITH SAID STUD AND DEFINING A CYLINDRICAL GROOVE SURROUNDING SAID STUD AND SAID GROOVE BEING OF SUCH SIZE AS TO RECEIVE THE SAID REDUCED DIAMETER END OF THE FIRST HUB PORTION ON SAID BODY PART, SAID HUB PORTIONS BEING OF SUBSTANTIALLY EQUAL OUTER DIAMETERS AND PROVIDING A WINDING SURFACE FOR WINDING THREAD THEREON. 